Thread rolling machine



March 14, 1967 I R. D. MORTON 3,308,642

THREAD ROLLING MACHINE Filed Nov. 5, 1963 6 Sheets-Sheet 1 INVENTOR ROBERT D. MORTON ATTORNEYS March 14, 1967 R. D. MO RTON I 3,308,642

THREAD ROLLING MACHINE Filed Nov. 5, 1963 s Shets-Sheet 2 INVENTOR. ROBERT D. MORTON WWW? ATTOR NEYS March 14, 1967 R. D. MORTON 3,308,642

THREAD ROLLING MACHINE Filed NOV. 5, 1965 5 Sheets-Sheet 5 FIG. 4

I +l INVENTOR I g 66 RQBERT D. MORTON ATTORNEYS United States Patent Office 3,308,642 Patented Mar. 14, 1967 3,308,642 THREAD ROLLING MACHINE Robert D. Morton, West Hartford, Conn., assignor to The Hartford Special Machinery Company, Simsbury, Conn., a corporation of Connecticut Filed Nov. 5, 1963, Ser. No. 321,484 1 Claim. (Cl. 72-88) This invention relates generally to thread rolling machines of the type useful for forming a thread on fasteners and the like and conventionally having stationary and reciprocable flat dies, for example the machine disclosed in the copending United States patent application of Robert D. Morton et al., Ser. No. 43,816, now Pat. No. 3,117,473, entitled, Thread Rolling Machine. More particularly, the present invention relates to an improved drive mechanism for the reciprocable die of a thread rolling machine.

It is a primary aim of the present invention to provide a new and useful drive mechanism of the type described which is adjustable for varying the stroke of the reciprocable die in accordance with the length of the die and the size of the threaded fastener.

It is another aim of the present invention to provide an improved drive mechanism which is useful for reducing the wear of the die and the vibration of the thread rolling machine.

It is a further aim of the present invention to provide an improved drive mechanism which enables the machine to be adjusted for optimum operation for the maximum production of threaded parts.

Other objects will be in part obvious and in part pointed out more in detail hereinafter. The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth, and the scope of the application of which will be indicated in the appended claim.

In the drawings:

FIG. 1 is a top view, partly broken away, of a thread rolling machine incorporating an embodiment of the present invention;

FIG. 2 is an enlarged view, partly broken away and partly in phantom, of a crank wheel subassembly of the thread rolling machine of FIG. 1;

FIG. 3 is an enlarged section view, partly broken away, taken substantially along line 3-3 of FIG. 1; and

FIG. 4 is an enlarged perspective exploded view, partly broken away and partly in section of the crank wheel subassembly.

Referring to the drawings in detail, there is illustrated in FIG. 1 a thread rolling machine of the type shown and described in the aforementioned patent application. The machine generally comprises an elongated table 12 to which is mounted a guide track 14 adapted for conveying blanks in line from a hopper (not shown) to adjacent a pair of cooperating stationary and reciprocable flat dies 16, 18, respectively. In the illustrated machine the stationary die 16 is detachably mounted to a stationary die block 19 by an adjustable clamp 20 and the reciprocable die 18 is mounted to a slide 22 by a similar adjustable clamp 24. In a conventional manner the slide 22 is mounted for reciprocable movement on a slide block 26 which can be laterally adjusted on the table 12 by a pair of adjusting screws 30 for setting the alignment and spacing of the stationary and reciprocable dies 16, 18.

In the usual manner, the guide track 14 is downwardly inclined so that the blanks are gravity fed between the rails 34 of the track. A combination gate and starting finger 36 is mounted at the open end of the track 14 for oscillatory movement generally parallel to and between the stationary and reciprocable dies 16, 18 and is driven for successively feeding a blank from the track 14 to between the leading edges of the dies 16, 18, as shown in FIG. 1, which feed-ing of the blank is timed to cooperate with the reciprocable movement of the slide 22.

A mechanism for driving the slide 22 includes a crank wheel 40 driven by a suitable speed reducer (not shown) through a spline drive shaft 42 (FIG. 3), the speed reducer being conventionally manually controllable as by a handle 43 for varying the speed of the crank wheel 40. The shaft 42 is supported on the table 12 by suitable bearings (not shown) for rotation about an axis which extends substantially perpendicular to the axis of reciprocable movement of the slide 22. For enclosing the spline drive shaft 42, an end cap 41 having an annular radial flange 43 received within a cooperating annulus in the crank wheel is suitably secured to the shaft as by fasteners 42.

The gate and starting finger 36 is driven by an annular cam 44 which is angularly adjustable on the wheel 40 and retained thereon by a plurality of clamping fingers 46 secured to the wheel by machine fasteners 48. A bell crank 50 having a cam follower (not shown) engageable with the circumferential edge of the cam 44 provides for translating the oscillatory movement of the cam follower into oscillatory movement of the gate and starting finger 36, which finger is adjustably mounted on a pivotal arm 52 operatively connected to the bell crank 50 by an adjustable variable length connecting rod 54.

For reciprocating the slie 22 an therefore the driven die 18, one end of a connecting rod or pitman arm 56 is eccentrically pivotally mounted to the crank wheel 40 and the other end of the connecting rod is pivotally connected to the slide as by a pivot pin 58. Accordingly, for each revolution of the crank wheel 40 the reciprocable die 18 is driven through one complete cycle with the stroke of the die 18 being dependent upon the eccentricity of the pivotal mounting of the connecting rod to the crank wheel 40.

In accordance with the present invention, the connecting rod 56 is eccentrically mounted to the crank wheel 40 by a crank pin, generally designated by the numeral 60, having a pair of eccentrically related crank pin portions 62, 64 of generally cylindrical configuration and with their axes extending parallel to the axis of rotation of the crank wheel 40. The crank pin portion 62 is rotatably received within a cooperating cylindrical opening 66 in the crank wheel 40, and an integral annular flange 68 coaxial with the crank pin portion 62 and interceived within a cooperating cylindrical recess 70 in the crank wheel 40. Preferably, a suitable spacer 72 is interposed between the crank pin flange 68 and a shoulder 74 of the crank wheel 40 for axially positioning the crank pin with respect to the crank wheel 40. The annular flange 68 has an integral annular lip 76 overlying the recess 70 and a portion of the radial flange 43 of the cap 41 for assisting in excluding foreign matter from the crank pin.

The crank pin portion 64 is rotatably mounted in a generally cylindrical opening 79 of the connecting rod 56 by an eccentric bearing sleeve 80 having an outer cylindrical surface 82 received within the opening 79 and an inner bronze bushing 83 with a cylindrical bearing surface 84 eccentric to the opening 79 and rotatably receivthe crank pin flange 76 and the eccentric bearing 80 and the bearing 80 is provided with a suitable radial flange 92 for axially locating the connecting rod 56 on the crank pin portion 64. A cap 94 overlying the cylindrical surface 84 of the eccentric bearing 80 is secured to the crank pin portion 64, as by fasteners 96 (FIG. 4) for retaining the bearing 80 against axial withdrawal from the crank pin 60, and a second cap 98, recessed for receiving the cap 94 and overlying the connecting rod 56, is secured to the hearing as by fasteners 100 (FIG. 4) for assisting in retaining the connecting rod against axial withdrawal from the bearing.

Referring now particularly to FIG. 4, the crank pin 60 is mounted for angular adjustment within the cylindrical opening 66 of the crank wheel and is adapted for being fixed to the crank wheel in its adjusted position by three pairs of diametrically opposed threaded fasteners 102, 103 and 104 (FIG. 2). Accordingly, in the illustrated embodiment the crank pin 60 can be angularly adjusted on the crank wheel 40 in two diametrically opposed positions where preferably the crank pin portion 64 is located at its minimum and maximum eccentricities, the maximum eccentric position being shown by phantom lines in FIG. 2, with respect to the axis of the crank wheel. As a result, the stroke of the connecting rod 56 may be adjusted for a maximum and a minimum amplitude which diifer by four times the eccentricity of the crank pin portion 64 with respect to the crank pin portion 62. For ease in adjusting the crank pin on the crank wheel 40, an axially extending locating pin 106 is secured to the intermediate flange 68 for downward extension through an opening 108 in the spacer 72 and for selective extension in the diametrically opposed locating holes 110 in the crank wheel. Additionally, a dowel locating pin 112 secured for upward extension from the intermediate flange 68 is received within a cooperating recess 114 of the washer for retaining the washer against angular movement about the crank pin portion 64.

Where necessary, after replacement of the stationary and reciprocable dies 16, 18, respectively, or after adjustment of the stroke of the connecting rod and reciprocable die, the stationary and reciprocable dies may be matched for properly aligning their opposed die surfaces by adjusting the efiective length of the connecting rod 56. This is accomplished in a convenient manner by angular adjustment of the eccentric bearing 80 in the opening 79 of the connecting rod, which adjustment is readily accomplished by loosening the fastener 90 and revolving the cap 98 for which purpose the cap is provided with a gear sector 116 and the connecting rod is provided with van opening 118 for a conventional gear key or wrench (not shown).

Lubrication is supplied to the bearing 80 from a supply passage 120 (FIG. 3) in the drive shaft 42 via a bored passage 122 in the crank wheel which is suitably plugged as by a dowel pin 124. An annular peripheral groove 126 is provided on the crank pin portion 62 for communication with the passage 122, and an axially extending passage 128 and a pair of laterally extending passages 130, 132 in the crank pin provide for connecting the groove 126 with the bearing 80, for which purpose a pair of diametrically opposed axially extending peripheral grooves or flats 134 are provided on the crank pin portion 64 to distribute the lubricant axially in the bearing 80. Additionally, the washer 91 is provided on its upper face with an eccentric annular lubricant groove 142 for distributing lubricant to the lower face of the bearing 80. The axial passageway 128 is provided with a suitable threaded plug 138 having a restricted passage or orifice which in conjunction with a similar plug 140 in the lateral passage 130 provides for restricting the lubricant flow to the bearing 80.

Thus it can be seen that the thread rolling machine of the present invention incorporates an advantageous and useful drive mechanism for the reciprocable die which allows for both ready adjustment of the stroke of the die and for mating the faces of the stationary and reciprocable dies. Such adjustments are particularly useful where it is desirable to use dies of a size which are different than the maximum size for the stroke of the machine. Accordingly, the dies 16, 18 can be, for example, substantially smaller than the maximum size for which the machine is designed for which purpose adaptors 146, 148 are used for mounting the stationary and reciprocable dies, respectively. The stroke can be adjusted in accordance with the size of the die, with a shorter stroke being preferable with a smaller die to reduce die wear and the wear and vibration of the machine. The r.p.m. of the crank wheel can thereby be increased without harmful machine vibration or excessive wear to increase the machine'productivity. Moreover with a shorter stroke, the machine speed can be increased a significant amount without reducing the time interval available for the introduction of the screw blank to between the dies at the beginning of the stroke.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claim.

I claim:

In a thread rolling machine having a reciprocable driven die, a rotatable drive member, a connecting rod having one end operatively connected to the reciprocable driven die, and connecting means for mounting the other end of the connecting rod to the rotatable drive member, the improvement wherein the connecting means is plurally eccentric to the axis of the rotatable drive member and comprises in combination an angularly adjustable eccentric sleeve bearing and an angularly' positionable crank pin, the connecting rod having at said other end bifurcated end portions providing a generally cylindrical opening receiving the eccentric sleeve bearing for angular adjustment therein and means connecting the bifurcated end portions for clamping the sleeve against angular movement in said opening, the drive member including a rotatable drive wheel having a generally cylindrical opening radially spaced from the axis of rotation of the wheel, said opening being provided with means for positioning the crank pin in a plurality of angularly related positions, said crank pin comprising a first crank pin portion received within the cylindrical opening of the rotatable drive wheel and a second crank pin portion eccentrically thereof rotatably received within the eccentric hearing, and means on said crank pin cooperating With said positioning means for securing the first crank pin portion to the rotatable drive wheel in one of said angularly related positions for fixing the eccentricity of the second crank pin portion with respect to the axis of rotation of the drive wheel and gear means fixed to said eccentric sleeve bearing adapted for angularly adjusting the sleeve bearing with an intermeshing gear Wrench to additional-1y vary the eccentricity of said other end of the connection rod relative to said axis.

References Cited by the Examiner UNITED STATES PATENTS RE 2,798 11/ 1867 WanZer 74-600 306,972 10/1884 Stiles 74-571 550,550 11/1895 Winssinger 7288 2,212,909 8/1940 Wiken 74600 3,180,178 4/1965 Brown et al. 74-600 CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner. 

